QuestionI bought this bike and am trying to get it to start. I noticed that after I installed a fuel filter (see thru type) that no fuel is getting thru when I turn it to the on position (straight up & down). Isn't the gas supposed to flow down by gravity or is a vacuum created sucking it out? Obviously without fuel it won't start. I unscrewed the bowl and the filter looks OK. What else can I try? Any ideas? Thanks, J.L.
AnswerA final thought on the petcock. The illustration isn't completely clear as to whether it has rivets in the lever plate or screws. Rivets can be carefully drilled out, holes rethreaded with 3mm or 4mm screws (threaded or self-tapping). Otherwise, if there are 2 screws on the plate, remove them and clean it all out. Otherwise, you have to find a new petcock or good used one.
Bill
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J.L.
First, use this reference for parts illustrations:
http://houseofmotorcycles.bikebandit.com/honda-motorcycle-cl125a-1968/o/m9112
Go to Fuel tank and you will see the construction of the petcock assy and the single screw that holds it to the bottom of the fuel tank. The front lever plate has two screws that are removed to access the 4 hole petcock gasket and the fuel passageways.
When you buy a used bike of any make/model, you have to do a full system check to see what is to be repaired, especially with the fuel system. This includes: gas cap(vent hole in the edge), fuel tank (no rust or corrosion), petcock (feed tube and reserve passages clear and clean), fuel line and carburetor (jets, float valve, air and fuel passages).
Fuel flow is gravity fed. If the internal passages inside the petcock are blocked from old fuel varnish or corrosion, then no fuel will pass. Blocked gas cap vent hole will also restrict fuel flow.
The ON position will feed about 3/4 of the fuel load. The reserve position will feed the rest of the fuel at the bottom of the tank. You will probably have to remove the petcock, disassemble it and use some small drill bits, turned by hand, to clean out the passageways. Good time to refresh the 4 hole gasket under the petcock lever. Not shown separately, but probably available from K&L accessory dealers.
If you haven't removed the carb float bowl to check condition of the jets and and debris down there, do it before you get all excited to start it up after you repaired the fuel flow to it.
Change the oil, while you are at it. Check valve clearances to .002" cold on intake/exhaust valves on Compression stroke. DO NOT jump start the bike with a car battery and do not try to start it without a good battery in the system. The permanent magnet charging systems can sometimes supply enough juice to light off the coil and plugs, but running the engine with a dead battery will kill the rectifier and usually damage all light bulbs that are in the circuits.
Bill Silver
